The team @ Skilldrive have put together a really interesting presentation which is targetted at developers but I think it works well for IT Professionals too. If you'd like to understand how the logon process works, how Windows handles encryption and authentication & storing secrets then it's worth a look.

The content includes over one hundred technical slides and the agenda's described as follows: 

"Security IDentifier, Logon Session, ACL, Privileges, LSA
Authentication protocols
Encryption, CryptoAPI
Data Protection API
Code based security
Role based security

You can download the slides for free from